GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS |
|
|
|
|
Effect of Kinetic Alfvén Waves on Electron Transport in an Ion-Scale Flux Rope |
Bin-Bin Tang1**, Wen-Ya Li1, Chi Wang1, Lei Dai1, Jin-Peng Han2 |
1State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 2Research and Development Center, China Academy of Launch Vehicle Technology, Beijing 100076
|
|
Cite this article: |
Bin-Bin Tang, Wen-Ya Li, Chi Wang et al 2018 Chin. Phys. Lett. 35 119401 |
|
|
Abstract At the Earth's magnetopause, the electron transport due to kinetic Alfvén waves (KAWs) is investigated in an ion-scale flux rope by the Magnetospheric Multiscale mission. Clear electron dropout around 90$^{\circ}$ pitch angle is observed throughout the flux rope, where intense KAWs are identified. The KAWs can effectively trap electrons by the wave parallel electric field and the magnetic mirror force, allowing electrons to undergo Landau resonance and be transported into more field-aligned directions. The pitch angle range for the trapped electrons is estimated from the wave analysis, which is in good agreement with direct pitch angle measurements of the electron distributions. The newly formed beam-like electron distribution is unstable and excites whistler waves, as revealed in the observations. We suggest that KAWs could be responsible for the plasma depletion inside a flux rope by this transport process, and thus be responsible for the formation of a typical flux rope.
|
|
Received: 06 August 2018
Published: 23 October 2018
|
|
|
|
Fund: Supported by the National Natural Science Foundation of China under Grant Nos 41474145, 41574159, 41731070 and 41504114, the Frontier Science Foundation of the Chinese Academy of Sciences under Grant No QYZDJ-SSW-JSC028, the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA15052500, and the Specialized Research Fund for State Key Laboratories of China. |
|
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|